yeah, you need to give a lot more information. What kind of micro controller are you using? When you say there's 5V at on the input pin, do you mean the Vcc/Vdd? is your ground connected properly (Vss). Some micro controllers are finicky about writing to the "latch" instead of the "port". Are you sure that the "port" operation is primary. Often times certain leads can double as a UART or SPI, etc so you have to make sure it's set to be a digital output first. If you have a schematic of your circuit that you help greatly, too. Even an MS Paint drawing would help.